Hectic bustle broke out this Sunday on the training ground of Borussia Dortmund in the city's northern suburb of Brackel.

While Nico Schlotterbeck, accompanied by medical staff, headed for further treatment, the bad news was officially announced 24 hours later.

Lucas Vazquez (L) of Real Madrid vies with Nico Schlotterbeck of Borussia Dortmund during the third round match of UEFA Champions League between Real Madrid and Borussia Dortmund in Santiago Bernabeu stadium, Madrid, Spain, Oct. 22, 2024. (Photo by Gustavo Valiente/Xinhua)

The defender's serious injury in the form of a torn meniscus in his left knee came as an unpleasant surprise ahead of the Black and Yellows' last eight rounds of the UEFA Champions League against Spanish giant Barcelona this Wednesday.

Despite the significant loss for the 2021 German Cup winner, the injury is bad news for German national coach Julian Nagelsmann.

The club's statement left no space for interpretation as the BVB made clear: Schlotterbeck is out for the rest of the season, which is including the UEFA Nations League final four (June 4-8) and the FIFA Club World Cup (June 15 to July 13).

While BVB coach Niko Kovac is forced to restructure his defense for the duel against the Spaniards, Nagelsmann is suffering from the second loss of one of his team pillars.

Last weekend, Bayern Munich genius Jamal Musiala limped off the pitch during a league encounter against Augsburg due to a muscle injury forcing him into an eight-week long break.

"That's a big setback for us," Dortmund sporting director Sebastian Kehl quoted while teammates delivered encouraging statements on social media.

"Schlotti was one of our best and a team leader this season. He can rely on all the support we can give," Kehl said, while the club confirmed the 25-year-old is out for all this season's competitions.

Reports speak of the BVB offering a long-term contract extension and a significant salary rise of up to twelve million euros for the defender, who currently has valid papers until 2027.

While the BVB and the player's management had worked on a new deal over the past weeks, reports say the offer remains despite the injury as the 2012 German Champion regards Schlotterbeck as the club's future figurehead.

Other reports speak of the defender as the team's future captain.

Schlotterbeck, in a tweet this Tuesday, called his recovery a "long and challenging journey" and announced to take a break on social media "to entirely focus on my recovery. I need that for me and a free mind."

He spoke about his determination and confidence to return in the best shape.

"I truly thank all for their encouraging support. That means a lot to me," he added, mentioning the wave of fans' postings.

The BVB defender promised to return "stronger than ever."

Reports speak of the BVB's decision to wait for Schlotterbeck's return and not sign an interim replacement in advance of the Club World Cup in a newly set-up transfer window.